Constant-current rotary converter.



No. 730,629.. PATBNTED JUNE 9. 1903.

- R. FLEMING.

CONSTANT CURRENT ROTARY CONVERTER. APPLICATION FILED NOV. 12, 1900 H0MODEL.

Witnesses Inventor:

Richard Fleming, .a

mamams pnzns cn. PHOTO-LYING WASNING'ION. 0.1:.

UNITED STATES Patented June 9, 1903.

PATENT OFFICE.

RICHARD FLEMING, OF Sl/VAMPSCOTT, MASSACHUSETTS, ASSIGNOR TO GEN- ERALELECTRIC COMPANY, A CORPORATION OF NEIV YORK.

CONSTANT-CURRENT ROTARY CONVERTER.

SPECIFICATION forming part of Letters Patent N 0. 730,629, dated June 9,1903.

Application filed November 12, 1900. Serial No. 36,185. (No model.)

To aZZ whom, it may concern:

Be it known that I, RICHARD FLEMING, a subject of the Queen of GreatBritain, resid ing at Swampscott, in the county of Essex, 5 State ofMassachusetts,haveinvented certain new and useful Improvements inConstant- Cnrrent Rotary Converters, of which the following is aspecification. 1

The principal object of the invention herein 10 described is toaccomplish the conversion of constant-potential alternating current intodirect current of constant volume. To acco1nplish this result, I havedevised a new type of rotary converter which, by reason of certain 1features of regulation which it possesses, en-

ables me to produce a constant direct current from a source ofconstant-potential alternating current. This converter differs in somerespects radically from the type of converter used for changingconstant-potential alternating current to constant-potential direct orthe reverse. Thus, for instance, the ar- In EttlllG-WlIlCllllg, insteadof being continuous, is of the open-coil variety, each coil of thewinding being connected at one end to a segment of the commutator, theother ends of the windings being connected, respectively, tocollector-rings, through which the windings receive alternating currentfrom a suitnot inherently essential in the practice of my invention.Another point of distinction is that the brushes which bear upon thecommutator, instead of being fixed during normal operation, are movedback and forth in order to vary the electromotive force impressed uponthe direct-current circuit, and thereby maintain a constant value ofcurrent therein.

A better understanding of my invention will be had by reference to thefollowing description,taken in connection with the accompanying drawing.

The points of novelty of my invention I will particularly set forth inthe appended claims.

The drawing represents my invention in diagram.

The field-poles of the converter are shown at 1 and 2. The armaturewhich cooperates 50 with these field-poles is provided in the presentinstance with three equally-spaced armaable source of supply, thoughthis feature is ture-coils 3, 4, and 5, which, by reason of this equalspacing, gives rise to induced electromotive forces having a three-phaserelation to each other. The converter is thus suitable for thetransformation of three-phase alternating current, this current beingsupplied over transmission-lines 6 to collector-rings and brushes,indicated generally at 6. The three windings 3, I, and 5 each have oneof their ends connected to one of the three collector-rings, as willreadilybe seen, the other ends of the windings being con nected,respectively, to the three commutator-seginents '7, 8, and 9,respectively, of a commutator built with the segments separated fromeach other by an air-space, as in the commutators usually employed forconstant-current machines.

Upon the commutator bear two sets of brushes 10 11 and 12 13, thebrushes 10 and 13 being carried by a rocker-arm 14, while the brushes 11and 12 are similarly mounted on another rocker-aria or brush-carryingring 15.

The brushes 10 and 11, constituting one set, are electrically connectedtogether through the medium of a self-induction coil 16, into the middlepoint in the length of which is connected a constant-current main 17. Ina similar manner the brushes 12 and 13 are connected together throughthe medium of a self-induction coil 18, into the middle of which istapped the constant-current conductor or main 19. The object of theseself-induction coils is to prevent too large a flow of current betweenbrushes to which they are connected, thereby materially reducingsparking at the commutator. y In order to produce the desired constantcurrent regulation, I make use of a magnetically controlled means forshifting the brushes about the commutator, and thereby adjusting theelectromotive force impressed upon the constant-current circuit. Themeans which I employ for this purpose may differ widely in characterwithout effecting the scope of my invention, since I do not wish to belimited to any particular form of blush-shifting mechanism. I have,however, in the drawing shown one form suitable for obtaining thebeneficial results of my invention. As shown, the brush-carrying yokesor rings 14c 15 have their projecting ends connected together by twolinks and 21, which form a sort of toggle-joint, which as the toggle ismoved backward and forward produces opposite movements of the yokes latand 15 either in one direction or the other, as the case may be. Thejoint between the links 20 21 is acted upon by a connecting-link 22,which is joined to one end of a magneticallyactuated lever 23, themovement of which is responsim to variations of. current in the constantcurrent circuit. lever 23 as acted upon by a magnet 24, the winding ofwhich is directly in series with the constant-current circuit 19. Themagnet acts to move the brushes in one direction, while a spring or theweight of the parts may be sufficient to move the brushes in theopposite position. The magnet alone may be used for purposes ofoperation, or if greater sensitiveness is desired a relay may be usedcontrolling the action of the magnetsuch, for example, as is used inconnection with the ordinary Thomson-Houston constant-current generator.As these minor features constitute no part of my present invention, Iconsider a detailed description unnecessary.

In exciting the field of the converter the direct current in theconsumption-circuit 25 may be passed through the field-winding 26 and27. If desired, however, a separate source of excitation may beemployed.

In starting the converter the brushes are separated so that the distancebetween any two is less than the arc spanned by one commutator-segment.The armature-windings are thus connected so as to form a closed circuit,and if supplied with alternating current through the collector-ringswill cause the converter to start into operation, the starting of theconverter being the same in principle as the starting of the ordinaryrotary converter. After the machine is gotten up to speed and the loadthrown on the further operation of the machine is automatic.

That I claim as new, and desire to secure by Letters Patent of theUnited States, is 1. The combination of a rotary converter I have shownthisprovided with collector-rings and a commutator, means for supplyingalternating current to said rotary converter, a consumptioncircuitconnected to brushes on the commutator, and magnetically-controlledmeans for shifting the brushes on the commutator as the load on theconsumption-circuit varies.

2. The combination of a rotary converter, means for supplying saidrotary converter with constant-potential alternating current, and meansfor supplying a variable load with constant current from said rotaryconverter.

3. The combination of a dynamo-electric machine .provided with anarmature having an open-coil winding, means for supplying said windingwith alternating current, and means for deriving from said armature aconstant direct current.

at. The combination of a dynamo-electric machine provided with anarmature, means for supplying said armature with a constantpotentialalternating current, and means for supplying a consumption-circuit witha constant direct current derived from said armature.

5. The combination of a dynamo-electric machine provided with acommutator and collector-rings, means for supplying constantpotentialalternating current to said collector rings, automatic means forshifting the brushes on the commutator, and a circuit fed from saidbrushes with direct current of constant value.

6. The combination of a dynamo-electric machine provided with acommutator and col lector-rings, means for supplying constantpotentialalternating current to said collector-rings, automatic meansfol-shifting the brushes on the commutator, and a circuit containingtranslating devices in series connected to said brushes.

In witness whereof I have hereunto set my hand this 9th day of November,1900.

RICHARD FLEMING.

lVitnesses:

DUGALD McK. McKILLoP, JOHN J. \VALKER.

